Study on overweight - Obesity status and related factors in preschool children in Ha Noi

JOURNAL OF SCIENCE OF HNUE Chemical and Biological Sci., 2014, Vol. 59, No. 9, pp. 131-138 This paper is available online at STUDY ON OVERWEIGHT-OBESITY STATUS AND RELATED FACTORS IN PRESCHOOL CHILDREN IN HANOI Nguyen Phuc Hung and Trinh Thi Van Faculty of Biology, Hanoi National University of Education Abstract. This study was conducted on 585 children, 3 to 5 years of age, at five preschools in inner and suburban Hanoi, 287 children in the inner city and 298 children in the suburban area. Anthropometric methods, sociological methods and WHO standards were used to evaluate the children’s overweight/obesity status and investigate factors related to the overweight-obesity status of the children. It was found that 13.85% of the children were overweight and 5.98% were obese. The percentage of overweight-obese children in inner Hanoi was greater than that in suburban Hanoi. Factors related to the overweight-obesity status of children included nutrition, physical activity, and family economic status. Keywords: Overweight, obesity, children, preschool, related factors. 1. Introduction In recent decades, the percentage of overweight-obese (OV-B) children has increased rapidly to become a worldwide health issue. According to the World Health Organization (WHO), obesity is a challenge of the new millennium and is one of the four health problems facing human beings (the four are HIV, cancer, obesity and drugs) [1]. In 2005, 20 million children worldwide under the age of 5 were overweight or obese. By 2011, this number rose to 42 million with nearly 35 million (83%) living in developing countries [2]. In Vietnam, the percentage of children who are OV-OB has been increasing rapidly [3]. In 2000, a survey revealed that 10% of elementary school children in Hanoi were OV-OB and 12% in Ho Chi Minh City were OV-OB [4, 5]. In 2011, the percentage of OV-OB Vietnamese children across the country was found to be 4.8%, a 6-fold increase since 2000 [6]. When so many very young children are OV-OB it is a serious public health problem. Apart from psychological trauma, children who are OV-OB are at greater risk for health Received December 5, 2014. Accepted December 23, 2014. Contact Nguyen Phuc Hung, e-mail address: hungnp@hnue.edu.vn 131 Nguyen Phuc Hung and Trinh Thi Van problems such as cardiovascular, gastrointestinal, respiratory and hormonal diseases. In addition, those children are at higher risk of metabolic disorders such as diabetes and cancer of the gallbladder, breast, colon, prostate or kidney. When children of preschool age are OV-OB, they are likely to grow up to be OV-OB adult if they do not experience a drastic change in diet and lifestyle [2, 4, 5]. Many studies have looked at the OV-OB status of children who are attending elementary school, junior high and high school. Most of these studies have looked at children in Hanoi and Ho Chi Minh City where socioeconomic conditions and quality of life has improved greatly for many. However, most of these studies did not look at the OV-OB status of preschool children. This study looks at the OV-OB status only of preschool aged children to obtain updated data and look at factors responsible for OV-OB in these young children. 2. Content 2.1. Materials and methods *Materials This study looked at 585 children from 3 to 5 years of age who were enrolled at five preschools in inner and suburban Hanoi: Anh Sao Preschool, Ba Dinh District (113 children); Sac Mau Preschool, Hoang Mai District (94 children); Trung Tu Preschool, Dong Da District (80 children); Van Phu Preschool, Thuong Tin District (188 children); Phu Linh Preschool and Soc Son District (110 children). Of the 585 children, 308 were male (52.65%) and 277 were female (47.35%). There were 287 inner city children (49.06%) and 298 suburban children (50.94%). Both the gender and number of children in the inner city and the suburban city were equivalent in the present study. *Methods Table 1. WHO malnutrition standards [2] (WHO malnutrition standards for children under five years old) Z-score Malnutrition status based on growth indicators Height-for-age Weight-for-age BMI-for-age > 3SD See note1 See note2 Obesity > 2 SD Normal Overweight > 1 SD Normal Possibly overweight3 0 (TB) Normal Normal Normal < -1 SD Normal Normal Normal < -2 SD Stunted4 Underweight Wasted < -3 SD Severely stunted4 Severely underweight Severely wasted 132 Study on overweight-obesity status and related factors in preschool children in Hanoi Notes. 1: A child in this range is very tall. Tallness is rarely a problem, unless it is so excessive that it may indicate an endocrine disorder such as a growth-hormone-producing tumor. Refer a child in this range for assessment if you suspect an endocrine disorder (e.g. if parents of normal height have a child who is excessively tall for his or her age). 2: A child whose weight-for-age falls in this range may have a growth problem, but this is better assessed from weight-for-length/height or BMI-for-age. 3: A plotted point above 1 shows possible risk. A trend towards the 2 z-score line shows definite risk. 4: It is possible for a stunted or severely stunted child to become overweight. The sample size followed the method described by Ha Huy Khoi, 1997 [7]. Anthropometric methods were used to measure standing height and body weight. Sociological methods were used to interview parents and teachers. Anthropometric indices such as date of birth, gender and date of measurement were analyzed using WHO AnthroPlus software which assessed the nutritional status of the children [8, 9]. The nutritional status provided by the AnthroPlus software was then transfered to SPSS software for a statistical analysis to evaluate relationships between factors and the anthropometric indices of the children in this study. The significance is based on a 5% level of probability. The formula for calculating the Z-score (SD-score) is: Z score = Observed valueMedian value of the reference population Standard deviation value of reference population 2.2. Results and discussion 2.2.1. Overweight and obesity status Table 2. Nutritional status of children at different ages Nutritional 3 years old 4 years old 5 years old Average status n % n % n % n % Obesity 6 2.96 14 7.57 15 7.62 35 5.98 Overweight 17 8.37 25 13.51 39 19.80 81 13.85 Possibly overweight 25 12.32 28 15.14 41 20.81 94 16.07 Normal 155 76.35 116 62.70 99 50.25 370 63.25 Wasted 0 0 2 1.08 3 1.52 5 0.85 Total 203 100 185 100 197 100 585 100 Table 2 shows that 5.98% of the children were obese, 13.85% of the children were overweight and up to 16.07% of the children might be overweight. In addition, 63.25% of the children were normal and 0.85% were wasted. The nutritional status of children worsened with age. The percentage of children who were OB increased with age, rising from 2.96% in the 3-year old group to 7.57% in 4-year old group to 7.62% in 5-year old 133 Nguyen Phuc Hung and Trinh Thi Van group. The percentage of children who were OV rose from 8.37% in the 3-year old group to 13.51% in the 4-year old group to 19.80% in the 5-year old group (P < 0.05). The percentage of children who might possibly be OV was also highest in the 5-year old group but it was not a significant difference. The percentage of OB children in the present study was higher than that of children in the city of Nha Trang in a study done by Nguyen Thin et al. in 1989. That study showed that 4.2% of 3 to 5-year olds were OB with a higher percentage of OB males than females [10]. However, a study carried out by Hoang Quy Tinh in 2013 in Hanoi found an even higher incidence of OV-OB than we did in this current study In that study, the percentage of OB children was 6.78% in the 3-year old group, 16.17% in the 4-year old group and 15% in the 5-year old group [12]. Table 3. Nutritional status of male and female children Nutritional status Male Female Average n % n % n % Obesity 20 6.50 15 5.42 35 5.98 Overweight 42 13.64 39 14.08 81 13.85 Possibly overweight 49 15.90 45 16.25 94 16.07 Normal 195 63.31 175 63.17 370 63.25 Wasted 2 0.65 3 1.08 5 0.85 Total 308 100 277 100 585 100 Table 3 shows that the nutritional status of male children differed from that of female children. the percentage of male children who were OB was 6.5% while 5.42% of the female children were OB. The percentage of male children who were OV was 13.64%while 14.08% of the female children were OV. The percentage of males whomight possibly be OV was 15.9% while 16.25% of the females might be OV. These differences were not statistically significant. Le Thi Khanh Hoa reported in 1993 that the percentage of OV-OB 3 to 5-year old children in Hanoi was 1.1% [10]. This percentage (1.1%) is much, much lower than that found in the present study (19.83%). This comparison shows that the incidence of OV–OB in the children of Hanoi is much greater than it was two decades ago. Due to the lack of data over the ensuing years, it is not possible to say whether this increase has been steady or has spiked upwards at times of rapid economic development and/or social change. As seen in Table 4, the percentage of OV-OB children in Anh Sao preschool was the highest (24.78%) and that of Phu Linh preschool was the lowest (P < 0.05). The percentage of OV-OB children of the Sac Mau, Trung Tu and Van Phu preschools was, 21.29%, 20% and 18.62%, respectively. 134 Study on overweight-obesity status and related factors in preschool children in Hanoi Table 4. Nutritional status of children at different preschools Nutritional status Anh Sao Sac Mau Trung Tu Van Phu Phu Linh n % n % n % n % n % Obesity 9 7.96 5 5.32 6 7.50 8 4.26 7 6.35 Overweight 19 16.82 15 15.97 10 12.50 27 14.36 10 9.10 Possibly overweight 20 17.70 17 18.08 14 17.50 28 14.90 15 13.64 Normal 65 57.52 56 59.57 49 61.25 123 65.42 77 70.00 Wasted 0 0 1 1.06 1 1.25 2 1.06 1 0.91 Total 113 100 94 100 80 100 188 100 110 100 When the preschools of the inner city (Anh Sao, Sac Mau and Trung Tu) are combined into one group and the preschools of the suburban areas (Van Phu and Phu Linh) are combined into another group, a clear difference in the incidence of OV–OB can be seen in the children of the two areas (Table 5). Table 5. A comparison of the nutritional status of inner city children with that of suburban area children Nutritional status Inner city Suburban city n % n % Obesity 20 6.97 15 5.03 Overweight 44 15.33 37 12.42 Possibly overweight 51 17.77 43 14.43 Normal 170 59.23 200 67.11 Wasted 2 0.70 3 1.01 Total 287 100 298 100 Table 5 shows that the rate of OV-OB in 3 to 5-year old children in the inner city (22.30%) was significantly higher than that of children in suburban area 17.45%) (P < 0.05). This difference might exist because children of the suburban area are not being given large amounts of expensive sweets and are therefore getting a more nutritious diet), it could because the more prosperous inner city families are providing and encouraged their children to eat more meat, or it could be because the more prosperous inner city children are less physically active due to their ownership of electronic (computer) toys. It’s likely that the difference is due a combination of all of these things. This is an area that deserves further study. The results of the present study are similar to the results of a study done by Tran Thi Xuan Ngoc in Hanoi in 1992. The author found that 4.9% of 3 to 5-year old Hanoi children were OV-OB. The percentage of OV-OB children in preschools in two inner city 135 Nguyen Phuc Hung and Trinh Thi Van districts, Hoan Kiem and Ba Dinh, were the highest (8.7% and 7.1%), followed by Hai Ba Trung District (6.5%). OV-OB in children was less prevalent in the suburban Hanoi preschools of Soc Son District (3.6%) and Hoai Duc District (3.1%) [11]. 2.2.2. Factors related to overweight and obesity status Odd ratio was used to determine factors related to overweight and obesity status of children. Table 6. Relationship between daily food and overweight-obesity status of children Daily food Nutritional status OR Overweight-obesity Normal Lipid-rich food 167 104 9.93 Lipid-poor food 43 266 6.50 < OR < 15.21 Table 6 shows that, the OV-OB status of children is closely related to their daily intake of food products Children who ate foods that are high in fat, such as fried food and fast food, were 9.93 times more likely to be OV-OB than those who’s diet was lower in fat, eating a proportionately greater amount of rice and vegetables. (OR = 9.93; 6.50 < OR < 15.21). Table 7. Relationship between tasting hobby and overweight-obesity status of children Tasting hobby Nutritional status OR Overweight-obesity Normal Tasting hobby free 154 159 3.65 Tasting hobby restricted 56 211 2.48 < OR < 5.37 As shown in Table 7, children who were 3.65 times more likely to be OV-OB. (OR = 3.65; 2.48 < OR < 5.37). Generally, children like to eat fried foods and fast foods. In addition, when children have tasting hobby free, they eat more than when they have tasting hobby restricted. Children eat more than normal regime, the risk of OV-OB can be high. Table 8. Relationship between entertainment activities and overweight-obesity status of children Activity Nutritional status OR Overweight-obesity Normal Oftentimes sitting in front of a TV or computer 146 135 3.97 Oftentimes engaged in outdoor physical activity 64 235 2.72 < OR < 5.80 136 Study on overweight-obesity status and related factors in preschool children in Hanoi Table 8 shows that children who oftentimes sit in front of a television or computer are 3.97 times more likely to be OV-OB than those who oftentimes engage in outdoor physical activity (OR = 3.97; 2.72 < OR < 5.80). It is a fact that physical activity consumes energy. When children oftentimes are engaged in physical activity, the calories that they consume are burned off. As the result, these children are less likely to be OV-OB. Table 9. Relationship between family economic status and overweight-obesity status of children Family economic Nutritional status OR status Overweight-obesity Normal Wealthy 128 147 2.46 Unwealthy 72 203 1.69 < OR < 3.57 Table 9 shows that children of wealthy families are 2.46 times more likely to be OV-OB than children of families that are not wealthy (OR = 2.46; 1.69 < OR < 3.57). It could be presumed that the adults of wealthy families have both the money needed and the desire to both provide nutritious foods, and see to it that their children do not eat non-nutritious foods. However, wealthy Vietnamese adults are oftentimes not well educated and not aware of nutritional content or needs. On the other hand, the adults who are not wealthy may not be able to provide their children with a nutritious diet in addition to not being aware of what constitutes a nutritious diet. The children of families that are not wealthy have one big advantage in that they are more likely to spent more time outdoors engaged in physical activities than the children of wealthy family who are given electronic toys and are encouraged to play with them indoors. 3. Conclusion The percentage of 3 to 5-year old Hanoi children who are obese was found to be 5.98% while 13.85% were overweight. The percentage of overweight-obese children in inner Hanoi was higher than that of children in suburban Hanoi. It was found that children are overweight or obese due to a combination of factors: poor nutrition, insufficient physical activity and economic status. The authors of the present study suggest that the percentage of OV-OB children in Hanoi is increasing rapidly and it is necessary to supply children a reasonable feeding regime along with physical activities in order to control and prevent excessive body weight and obesity. REFERENCES [1] World Health Organization, 2004. Obesity: preventing and managing the global epidemic. Singapore Publisher, Printed in Singapore, pp. 101-138. 137 Nguyen Phuc Hung and Trinh Thi Van [2] Wolrd Health Organization, 2012. Global strategy on diet, physical activity, and health: childhood overweight and obesity. Geneva. [3] Ministry of Health, 2003. Biological Indexes of the Vietnamese in 1990s. Medical Publishing House, Hanoi. [4] Le Thi Hai et al., 2002. Study on risky factors responsible for obesity in 6 year-old to 11 year-old pupils in Ha Noi. Issue of overweight - obesity and public health, Vietnam National Institute in Nutrition, Hanoi, pp. 229-245. [5] Nguyen Thi Kim Hung et al., 2002. Overweight and obesity status in citizens in Ho Chi Minh city from 1996 to 2001. Issue of overweight-obesity and public health. Vietnam National Institute in Nutrition, Hanoi, pp. 109-120. [6] Vietnam National Institute in Nutrition, 2013. Malnutrition Percentages of under-five year-old children in ecological regions in 2013. Hanoi. [7] Ha Huy Khoi, 1997. Epidemic methods in studing nutrition. Medical Publishing House, Hanoi. [8] Hoang Quy Tinh, Nguyen Huu Nhan, Nguyen Thi Thuy Linh, 2009. Applying WHO Anthro Software in Studying some Anthropometric Measurements. Journal of Army Bio-Pharmacy, Vol. 34, pp. 1-5. [9] World Health Organization, 2009. WHO AnthroPlus for Personal Computers Manual: Software for assessing growth and development of the world’s children. Geneva. [10] Le Thi Khanh Hoa,1996. Evaluation nutritional status and related factors in 3 year-old to 5 year-old children in Ha Noi. Hanoi Medical University, pp. 25-26. [11] Tran Thi Xuan Ngoc, 2011. Status and treating ecffeciency of informating and educating model on overweight and obesity. Vietnam National Institute in Nutrition, Hanoi. [12] Nguyen Thin et al.,1999. Overweight and obesity status in 3 year-old to 5 year-old children in Nha Trang. Journal of Medicine, Vol. 3, pp. 57-62. 138